fix: removes use of slices.DeleteFunc because it zeros the elements a…

…nd doesn't remove those from obj list

cmd/clusterctl/client/cluster/cert_manager.go

@@ -19,7 +19,6 @@ package cluster
 import (
 	"context"
 	_ "embed"
-	"slices"
 	"time"
 
 	"github.com/blang/semver/v4"
@@ -346,9 +345,13 @@ func (cm *certManagerClient) shouldUpgrade(desiredVersion string, objs, installO
 	// removes resources that are generated by the kubernetes API
 	// this is relevant if the versions are the same, because we compare
 	// the number of objects when version of objects are equal
-	objs = slices.DeleteFunc(objs, func(obj unstructured.Unstructured) bool {
-		return obj.GetKind() == "Endpoints" || obj.GetKind() == "EndpointSlice"
-	})
+	newObjs := []unstructured.Unstructured{}
+	for _, o := range objs {
+		if !(o.GetKind() == "Endpoints" || o.GetKind() == "EndpointSlice") {
+			newObjs = append(newObjs, o)
+		}
+	}
+	objs = newObjs
 	for i := range objs {
 		obj := objs[i]